lkml.org 
[lkml]   [2007]   [Apr]   [22]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: Wrong free clusters count on FAT32
    Hi Bodo :)

* Bodo Eggert <7eggert@gmx.de> dixit:
> OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> wrote:
> >> * Juergen Beisert <juergen127@kreuzholzen.de> dixit:
>
> >>> So the last free sector count is also stored. When mounting this
> >>> filesystem you don't need to walk through the whole FAT to calculate
> >>> the available space, you can use this "cached" value instead. And this
> >>> cached value seems not to be updated in your portable device.
> >>
> >> It doesn't, certainly, but Windows doesn't care. Moreover, the
> >> device doesn't seem to recalculate the value on every run (unless it
> >> does it lightning fast!), so maybe the number is stored elsewhere (the
> >> count can be stored in many places as far as I've read, but I don't know
> >> the details).
>
> AFAIR it's stored twice on FAT32, once in a backup sector and once in the
> superblock or extended superblock (don't remember, I think it was the
> extended ~). It's not stored on FAT{12,16}.

I hadn't noticed the same problem with FAT16 pendrives, so I
suspected that. Thanks for confirming :)

Raúl Núñez de Arenas Coronado

--
Linux Registered User 88736 | http://www.dervishd.net
It's my PC and I'll cry if I want to... RAmen!
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2007-04-22 22:11    [W:0.066 / U:0.628 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site